Abstract Wrinkled graphene shows an enhanced photoelectric effect owing to the opening of a bandgap induced by stress. Here, bismuth (Bi) nanorods array with trigonal orientation are assembly grown on silicon substrates by molecular beam epitaxy. Single layer graphene (SLG) is transferred on top of the Bi nanorods array to make flat SLG forming into wrinkles. Through the application of visible-infrared and Fourier transform infrared spectroscopies, enhanced optical absorption in the wrinkled SLG/Bi nanorod heterostructures was observed. Raman spectral analysis showed a large 2D peak shift of up to −11 cm−1 compared with that of flat graphene on silicon wafers. This finding indicates the existence of a tensile stress induced opening of the band gap. Nonlinear current-voltage characteristics confirmed the opening of an intrinsic bandgap in the wrinkled graphene. The on-off ratio was shown to increase by 30 times and the dark current was remarkably suppressed by 3–4 orders of magnitude for the Bi nanorods/wrinkled SLG heterostructures when compared with those properties of flat SLG on silicon.

中文翻译：

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褶皱单层石墨烯/铋纳米棒异质结构中的巨大光吸收和低暗电流特性

摘要 由于应力引起的带隙打开，皱纹石墨烯显示出增强的光电效应。在这里，具有三角形取向的铋 (Bi) 纳米棒阵列通过分子束外延在硅衬底上组装生长。单层石墨烯 (SLG) 被转移到 Bi 纳米棒阵列的顶部，使平坦的 SLG 形成皱纹。通过可见红外光谱和傅里叶变换红外光谱的应用，观察到起皱的 SLG/Bi 纳米棒异质结构中的光吸收增强。拉曼光谱分析显示，与硅晶片上的平面石墨烯相比，2D 峰位移高达 -11 cm-1。这一发现表明存在由张应力引起的带隙打开。非线性电流-电压特性证实了褶皱石墨烯中固有带隙的打开。与硅上平面 SLG 的特性相比，Bi 纳米棒/皱纹 SLG 异质结构的开关比增加了 30 倍，暗电流显着抑制了 3-4 个数量级。